Power steering loss & speedo on 0

Ok speedo was working and steering now I have both not working.
I read that adding a second earth to the back of the clocks multi plug solves both problems...
Well ok... Ill try it but I need to know which wire is the earth please.

Hi P1darbs

Thanks for the tips on accessing the maxi fuses in the engine bay fuse box!

P1darbs wrote:I read that adding a second earth to the back of the clocks multi plug solves both problems...

I have not heard of this, and would always go down the route of finding why the original earth has failed and fix that.
But for information, from my diagrams the Instrument panel earth is the Green/Yellow wire that is on pin 9 of the 18 way black connector attached to the instrument panel. The earth is shared with various dashboard switches, the A/C control panel and the handbrake switch, but no mention of the power steering ECU, so it will be good to hear how this fix goes.

Had a bit of a break from the C3 but now need to get this sorted... I agree with your comments actually finding why the original earth failed is better than adding another.
But for ease I added the second earth and nothing changed I have cleaned all the earth points I could find on the car.
I have now bought a speed sensor spindle... Do you know where the speed sensor is located?

Lol found the location of the speed sensor... It's a the back of the gearbox and has to be accessed from under the car. it does require some patience as access is restricted.
once you remove the electrical connection & the 6mm allen key bolt you can twist & remove the sensor complete with the spindle.
you will need a bowl to catch the gearbox oil and be aware that this really smells so avoid getting it on your skin wear disposable gloves.
Once removed refitting is a simple reversal.
I cleaned and inspected the contacts and replaced it but it hasn't fixed the power steering or speedo so I have ordered a new one from eBay £15. Local Citroen want £48.

we too have this loss of power steering and speedo dropping to o mph problem.... did swapping the speedo sensor at the gearbox help?

keved wrote:we too have this loss of power steering and speedo dropping to o mph problem.... did swapping the speedo sensor at the gearbox help?

The first thing to do, if you haven't already (sorry to bring it up if you have) is to see if you have ABS or not.

On models of C3 with ABS, the speedo reading is taken from the ABS system - the wheel sensor information.

On models of C3 that don't have ABS, there is no ABS wheel sensor, so there is a sensor fitted to the gearbox that gives the computer systems the road speed signal.

The road speed signal is also used by the electronic power steering ecu to compute the level of assistance required.

We have only recently purchased a second hand C3 LX 1.4 petrol with 1 previous owner and have experienced the same issue.

All of a sudden (2 days after purchase) the speedometer now permanently reads zero (also the steering now feels tight and the engine regularly cuts out when braking to a stop).

Has anyone managed to establish the cause of this (apparently common) fault ?

did you change the speed meter located on the head of transmission behind motor? changing it may solve th eproblem, scan it if the speedmeter give faults then it needs to be changed, if no then it may be electrical faults maybe because you are not using convenient spark plugs ( you need double head ones) or because of the coil or dynamo giving wrong electricity signals...

Hi, I have just bought a C3 1.4 and my one has this problem. The speedo is at 0, heavy steering and cuts out at junctions. The person I got it from said it needs a new ecu. My code reader said speed sensor so i got one from breakers and no luck. Iv also tried the earth on the back of the display and still nothing. Has any one done a fix for this fault as I can't see a solution anywhere. I would like to be sure first before committing to buying a ecu and lock set. Many thanks.

Hendy777 wrote: ↑Sat Mar 11, 2017 1:51 pm Hi, I have just bought a C3 1.4 and my one has this problem. The speedo is at 0, heavy steering and cuts out at junctions. The person I got it from said it needs a new ecu. My code reader said speed sensor so i got one from breakers and no luck. Iv also tried the earth on the back of the display and still nothing. Has any one done a fix for this fault as I can't see a solution anywhere. I would like to be sure first before committing to buying a ecu and lock set. Many thanks.

Citroen C3 with ABS gets it speedo (and power steering) data from the wheel sensors ABS ECU.

The Citroen C3 that don't have ABS pick up the speed signal from the gearbox sensor discussed above.

Find out which system your C3 uses and it will put you in a much better position to make the diagnosis.

All of these faults can be diagnosed with the lexia tool (topic here).